Lighting units are already known which are based on the chemiluminescent emission generated by the mixing of two liquids. One system, which is used commercially on a wide scale, is described, for example, in U.S. Pat. No. 3,576,987; it consists of a first liquid solution in a hollow tube made of a light transmitting and slightly flexible plastic, and a second liquid solution contained in a glass vial or glass capillary which floats in the first solution. When the user bends the tube, the internal glass unit breaks and releases the second solution which mixes with a first solution. This system is not without drawbacks. The presence of a sealed glass vial, or a sealed glass capillary, has an unfavorable effect on the solutions used and over long periods of time it causes changes in the solutions. The presence of glass debris, sometimes with sharp points, is not always welcomed by the users who may fear, whether correctly or incorrectly, that the external envelope could break accidentally. Finally, in the fairly frequent case of a glass container in the form of an elongated capillary, there exists the danger of premature breaking during handling operations.
In addition, systems have been proposed--none of which is commercially used yet--which are based on the presence of two compartments which are temporarily separate and exist in the same closed container or recipient. The separation is achieved either by a temporary pinching or folding of the container, or by the existence of a medial separation wall which can be eliminated by breaking, tearing or unclipping. Several proposals of this type have been described in U.S. Pat. Nos. 3,749,620, 3,539,794, 3,893,938, 3,808,414, 4,061,910 and 3,149,943 as well as in French Patent No. 87 11 296. In the above-mentioned U.S. Pat. No. 3,749,620, a long list of earlier patents is given, patents which have disclosed the existance of containers with two components which are to be mixed. One should observe in this regard, to be complete, that in most cases these are not chemiluminescent liquids, and in many cases, the substances are not necessarily liquids.
Consequently, there is always a need for the economic production of articles which generate chemiluminescent light, and which, by nature, are intended for a single use.